Custom ZoomPanLayout for https://github.com/moagrius/TileView/ that allows restricting the scroll bounds with an arbitrary rectangle

ZoomPanLayout.java

public class ZoomPanLayout extends ViewGroup implements
	GestureDetector.OnGestureListener,
	GestureDetector.OnDoubleTapListener,
	ScaleGestureDetector.OnScaleGestureListener,
	TouchUpGestureDetector.OnTouchUpListener {
		
	private boolean isFinderActive(){
		// return true if FinderView is available and visible
	}
		
	private Rect getFinderRect() {
		// return a Rect that represents the bounds of the visible FinderView
	}

	private void calculateMinimumScaleToFit() {
		int calcWidth = getWidth();
		int calcHeight = getHeight();

		if (isFinderActive()) {
			calcWidth = (int) getFinderRect().width();
			calcHeight = (int) getFinderRect().height();
		}

		mMinimumScaleX = calcWidth / (float) mBaseWidth;
		mMinimumScaleY = calcHeight / (float) mBaseHeight;
		float recalculatedMinScale = calculatedMinScale(mMinimumScaleX, mMinimumScaleY);
		if (recalculatedMinScale != mEffectiveMinScale) {
			mEffectiveMinScale = recalculatedMinScale;
			if (mScale < mEffectiveMinScale) {
				setScale(mEffectiveMinScale);
			}
		}
	}
	
	protected int getScrollLimitX() {
		if (isFinderActive()) 
			return mScaledWidth - (int) getFinderRect().right + getOffsetX();
		
		return mScaledWidth - getWidth();
	}

	protected int getScrollLimitY() {
		if (isFinderActive())
			return mScaledHeight - (int) getFinderRect().bottom + getOffsetY();
		
		return mScaledHeight - getHeight();
	}

	protected int getScrollMinX() {
		if (isFinderActive())
			return -(int) getFinderRect().left + getOffsetX();
		
		return 0;
	}

	protected int getScrollMinY() {
		if (isFinderActive())			
			return -(int) getFinderRect().top + getOffsetY();
		
		return 0;
	}		
}